We’ve spent the week looking at possible contenders to the presidency if there’s a sudden leadership vacuum in Russia. Here’s a look back at the prime contenders, as well as your chance to weigh in on who’s next atop the Kremlin.

Nikolai Patrushev: The hard-liner former Putin colleague in the KGB spits out some of the sharpest anti-Western rhetoric in the Kremlin, and the West has responded in kind with sanctions. The security chief remains a top aide, surviving purges of the Putin inner circle.

Sergei Shoigu: The defense minister predated Putin as a political phenomenon in the 1990s but has faithfully stayed in the background — and at the president’s side on his adventure trips, including staging the famous photo of Putin shirtless atop a horse.

Alexei Navalny: Russia’s chief rabble-rouser continues to be harassed and arrested as he investigates corruption and campaigns against Putin in the 2018 election. But don’t mistake him for the great liberal hope: Navalny has ties to right-wing nationalists.

Alexei Kudrin: The former finance minister is credited with steering Russia through the global financial crisis and is a longtime buddy of Putin’s. But the Western-friendly moderate appeared at an unsanctioned protest in 2011, raising doubts about his loyalty.

Vyacheslav Volodin: The policy aide and uber-loyalist has helped to crack down on protests and once said “there is no Russia” without Putin. Now the speaker of the Duma, the lower house of Parliament, he’s politically ambitious and honing his populist skills.